浅析地铁车站设计

地铁车站设计是一个综合性很强的工作,要与线路、行车、信号、通风空调等专业紧密相关,各个专业之间的优化组合对于降低地铁车站造价有着非常重要的作用。详细介绍了地铁车站的平面布局设计,合理的车站布局设计,可以有效减少地铁的工程建设费用。     

城市出租车行业群发性事件风险预警方法

为实现对城市出租车行业的实时监测和预警,避免或减轻出租车行业群发性事件造成的不良影响,从出租车市场供给需求指标、市场价格与经营成本指标、市场经营环境指标、相关政策指标四个方面构建出租车行业群发性事件风险评估指标体系,利用层次分析法和加权平均法建立相应的风险评估模型,提出风险预警级别划分标准,并采用累积频率曲线法确定各风险等级的阈值。基于安徽省出租车行业近年来的出租车群发性事件对模型进行了标定,并以安徽省蚌埠市为例进行了应用验证,结果表明本文提出的方法具有较好的实用性,可实现对城市出租车行业群发性事件的风险预警和风险源的识别。     

基于RBF的城市快速路交通异常事件自动检测算法分析

通过对城市快速路交通异常事件自动检测方法的分析,提出用MATLAB神经网络工具箱建立交通异常事件自动检测RBF模型,并通过采集的实测交通异常事件数据对RBF神经网络在自动检测算法中进行仿真研究。结果表明RBF神经网络算法具有检测率高、误报率低和检测速度快等优点。     

高速公路交通事件线性模型及车流波分析

高速公路由于交通事件的发生导致正常交通流发生改变,为了消散车流拥挤或阻塞,减少排队延误,应采取一定干预措施。运用流体力学车流波理论,分析了交通事件和干预措施综作用下对车流状态的影响,建立了关于车速与交通密度线性模型下的车流波波速模型,这些模型为有效确定事件处理方案,尽快消除拥挤或阻塞提供了理论依据。     

Contrastive Analysis of Working Face Stability in Cases of Climbing Excavation and Horizontal Excavation北大核心CSCD

Restricted by site and construction period of ancillary structure of metro project, climbing excavation is often adopted. In order to determine tunnel face’s stability, the stabilities of working face in the cases of climbing ex- cavation and horizontal excavation were analyzed by theoretical analysis and numerical simulation. With upperbound limit analysis, the affected scope and positions of failure zone were compared; the position of equivalent strain zone and the law of horizontal displacement changes were studied by simulation analysis. The results show that the scope of failure zone caused by climbing excavation was slightly larger than that by horizontal excavation and the po- sition of affected zone is slightly lower than that by horizontal excavation; the horizontal displacement caused by climbing excavation within a scope of 0-1/3 height of tunnel face is slightly larger than that by horizontal excavation while it is slightly smaller beyond the scope of 0-1/3 height of tunnel face; the maximum horizontal displacements in the cases of climbing and horizontal excavation both occur at the place where is 1/3 height of work face and the de- formation of work face in the case of climbing excavation is not larger than that of horizontal excavation; the work face stabilities are mostly the same in the cases of climbing and horizontal excavation without regard to advanced support, and the work face stability is to be guaranteed with proper advanced support. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

多风险点地铁暗挖区间施工技术研究

基于西安地铁二号线第15标段环境条件十分复杂,重、难风险源较多且连续性强的特点,文章从隧道穿越地裂缝段、公路立交、地下暗涵、人行天桥等方面深入分析了多风险点区间暗挖的关键技术．提出了相应的处理措施,为类似地铁工程施工提供借鉴。     

地铁主控仿真培训系统的初步研究

随着地铁系统的迅速发展及其在轨道交通运输系统中重要性的不断提高,现有的地铁监控系统已不能满足对整个地铁系统进行全面监控的要求,一种新型的综合监控系统——池铁主控系统应运而生．本文在介绍地铁主控系统的基础上,设计了一种地铁主控仿真培训系统实现方案,重点介绍系统的体系结构、硬件／软件设计思路、数据库设计及软件模块功能。     

我国地铁与建筑物合建体系研究评述

在总结我国分离式和合并式合建建筑振动转播路径和动力特性的基础上,评述不同类型的既有合建建筑动力响应及振动控制的工程实测和数值分析的研究现状。结果表明:相较于临近地铁建筑,合建建筑在振动强度、激振频段、低频敏感频段、水平振动量级和振动形态等方面具有显著不同;为改善合建建筑的振动环境,可通过降低车体重量、改善轮轨接触面和选择适合的减振轨道与扣件等手段对振源进行振动控制,还可采用整体浮置或局部浮置等隔振方法进行上部结构振动控制。为此,应在适用于合建建筑的通用耦合计算模型、减振轨道实际控制效果、制定匹配合建建筑的振源频率、开发具有针对性的隔振装置产品、浮置隔振中参数优化与关键部位的构造设计等领域进行深化研究。     

Does public transit improvement affect commuting behavior in Beijing,China? A spatial multilevel approach

Developing countries like China have experienced substantial city transformations over the past decade. City transformations are characterized by transportation innovations that allow individuals to access to speedy commuting modes for work activities and offer potential influences on commuting behavior. This paper examines the potential effects of subway system expansion in Beijing on commuting behavior. Our methodological design controls for spatial effects by employing Bayesian multilevel binary logistic models with spatial random effects. Using cross-sectional individual surveys in Beijing, the results suggest that there is a significant rise in subway commuting trips while non-motorized and bus commuting trips are reduced with the new subway expansion. Model comparison results show evidence about the presence of spatial effects in influencing the role of built environment characteristics to play in the commuting behavior analysis.     

Reprint of: Modelling the impact of traffic incidents on travel time reliability

Traffic incidents are recognised as one of the key sources of non-recurrent congestion that often leads to reduction in travel time reliability (TTR), a key metric of roadway performance. A method is proposed here to quantify the impacts of traffic incidents on TTR on freeways. The method uses historical data to establish recurrent speed profiles and identifies non-recurrent congestion based on their negative impacts on speeds. The locations and times of incidents are used to identify incidents among non-recurrent congestion events. Buffer time is employed to measure TTR. Extra buffer time is defined as the extra delay caused by traffic incidents. This reliability measure indicates how much extra travel time is required by travellers to arrive at their destination on time with 95% certainty in the case of an incident, over and above the travel time that would have been required under recurrent conditions. An extra buffer time index (EBTI) is defined as the ratio of extra buffer time to recurrent travel time, with zero being the best case (no delay). A Tobit model is used to identify and quantify factors that affect EBTI using a selected freeway segment in the Southeast Queensland, Australia network. Both fixed and random parameter Tobit specifications are tested. The estimation results reveal that models with random parameters offer a superior statistical fit for all types of incidents, suggesting the presence of unobserved heterogeneity across segments. What factors influence EBTI depends on the type of incident. In addition, changes in TTR as a result of traffic incidents are related to the characteristics of the incidents (multiple vehicles involved, incident duration, major incidents, etc.) and traffic characteristics.